365 research outputs found

    COVER Project and Earth resources research transition

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    Results of research in the remote sensing of natural boreal forest vegetation (the COVER project) are summarized. The study objectives were to establish a baseline forest test site; develop transforms of LANDSAT MSS and TM data for forest composition, biomass, leaf area index, and net primary productivity; and perform tasks required for testing hypotheses regarding observed spectral responses to changes in leaf area index in aspen. In addition, the transfer and documentation of data collected in the COVER project (removed from the Johnson Space Center following the discontinuation of Earth resources research at that facility) is described

    New dimension analyses with error analysis for quaking aspen and black spruce

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    Dimension analysis for black spruce in wetland stands and trembling aspen are reported, including new approaches in error analysis. Biomass estimates for sacrificed trees have standard errors of 1 to 3%; standard errors for leaf areas are 10 to 20%. Bole biomass estimation accounts for most of the error for biomass, while estimation of branch characteristics and area/weight ratios accounts for the leaf area error. Error analysis provides insight for cost effective design of future analyses. Predictive equations for biomass and leaf area, with empirically derived estimators of prediction error, are given. Systematic prediction errors for small aspen trees and for leaf area of spruce from different site-types suggest a need for different predictive models within species. Predictive equations are compared with published equations; significant differences may be due to species responses to regional or site differences. Proportional contributions of component biomass in aspen change in ways related to tree size and stand development. Spruce maintains comparatively constant proportions with size, but shows changes corresponding to site. This suggests greater morphological plasticity of aspen and significance for spruce of nutrient conditions

    Monitoring global vegetation

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    An attempt is made to identify the need for, and the current capability of, a technology which could aid in monitoring the Earth's vegetation resource on a global scale. Vegetation is one of our most critical natural resources, and accurate timely information on its current status and temporal dynamics is essential to understand many basic and applied environmental interrelationships which exist on the small but complex planet Earth

    Sodium Dynamics in a Northern Ecosystem

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    Grid-Competitive Residential and Commercial Fully Automated PV Systems Technology: Final technical Report, August 2011

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    Under DOE's Technology Pathway Partnership program, SunPower Corporation developed turn-key, high-efficiency residential and commercial systems that are cost effective. Key program objectives include a reduction in LCOE values to 9-12 cents/kWh and 13-18 cents/kWh respectively for the commercial and residential markets. Target LCOE values for the commercial ground, commercial roof, and residential markets are 10, 11, and 13 cents/kWh. For this effort, SunPower collaborated with a variety of suppliers and partners to complete the tasks below. Subcontractors included: Solaicx, SiGen, Ribbon Technology, Dow Corning, Xantrex, Tigo Energy, and Solar Bridge. SunPower's TPP addressed nearly the complete PV value chain: from ingot growth through system deployment. Throughout the award period of performance, SunPower has made progress toward achieving these reduced costs through the development of 20%+ efficient modules, increased cell efficiency through the understanding of loss mechanisms and improved manufacturing technologies, novel module development, automated design tools and techniques, and reduced system development and installation time. Based on an LCOE assessment using NREL's Solar Advisor Model, SunPower achieved the 2010 target range, as well as progress toward 2015 targets

    Unsettling sustainability: the poetics of discomfort

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    peerreview_statement: The publishing and review policy for this title is described in its Aims & Scope. aims_and_scope_url: http://www.tandfonline.com/action/journalInformation?show=aimsScope&journalCode=rgrl2

    A critical interpretive synthesis of evidence and values in recommendations to disinvest from population Screening

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    β€’ the interplay between values and evidence in screening policy β€’ methods of an ongoing systematic review β€’ examples of disinvestment decision

    Constructing a new understanding of the environment under postsocialism

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    This paper introduces a special grouping of papers on the theme of the environment and postsocialism. After the collapse of state socialism in Europe between 1989 and 1991, many immediate approaches to environmental reconstruction assumed that economic liberalisation and democratisation would alleviate problems. Since then, critics have argued that these proposed solutions were themselves problematic, and too closely reflected Western European and North American conceptions of environmental quality and democracy. The result has been a counterreaction focusing on detail and specificity at national levels and below. In this paper, we summarise debates about the environment and postsocialism since the period 1989 - 91. In particular, we examine whether an essentialistic link can be made between state socialism and environmental problems, and how far civil society -- or environmentalism -- may result in an improvement in perceived environmental quality. Finally, we consider the possibility for developing an approach to the environment and postsocialism that lies between crude generalisation and microscale studies

    Predicting Maximum Tree Heights and Other Traits from Allometric Scaling and Resource Limitations

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    Terrestrial vegetation plays a central role in regulating the carbon and water cycles, and adjusting planetary albedo. As such, a clear understanding and accurate characterization of vegetation dynamics is critical to understanding and modeling the broader climate system. Maximum tree height is an important feature of forest vegetation because it is directly related to the overall scale of many ecological and environmental quantities and is an important indicator for understanding several properties of plant communities, including total standing biomass and resource use. We present a model that predicts local maximal tree height across the entire continental United States, in good agreement with data. The model combines scaling laws, which encode the average, base-line behavior of many tree characteristics, with energy budgets constrained by local resource limitations, such as precipitation, temperature and solar radiation. In addition to predicting maximum tree height in an environment, our framework can be extended to predict how other tree traits, such as stomatal density, depend on these resource constraints. Furthermore, it offers predictions for the relationship between height and whole canopy albedo, which is important for understanding the Earth's radiative budget, a critical component of the climate system. Because our model focuses on dominant features, which are represented by a small set of mechanisms, it can be easily integrated into more complicated ecological or climate models.National Science Foundation (U.S.) (Research Experience for Undergraduates stipend)Gordon and Betty Moore FoundationNational Science Foundation (U.S.) (Graduate Research Fellowship Program)Massachusetts Institute of Technology. Presidential FellowshipEugene V. and Clare Thaw Charitable TrustEngineering and Physical Sciences Research CouncilNational Science Foundation (U.S.) (PHY0202180)Colorado College (Venture Grant Program

    ASHG/ACMG Report Points to Consider: Ethical, Legal and Psychosocial Implications of Genetic Testing in Children and Adolescents

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    In 1995, the American Society of Human Genetics (ASHG) and American College of Medical Genetics and Genomics (ACMG) jointly published a statement on genetic testing in children and adolescents. In the past 20 years, much has changed in the field of genetics, including the development of powerful new technologies, new data from genetic research on children and adolescents, and substantial clinical experience. This statement represents current opinion by the ASHG on the ethical, legal, and social issues concerning genetic testing in children. These recommendations are relevant to families, clinicians, and investigators. After a brief review of the 1995 statement and major changes in genetic technologies in recent years, this statement offers points to consider on a broad range of test technologies and their applications in clinical medicine and research. Recommendations are also made for record and communication issues in this domain and for professional education
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